Chapter 14 - Modular and Incremental Design

Abstract

This chapter focuses on the concepts of modular and incremental design in field-programmable gate arrays (FPGA). Modular design, also known as team design, refers to the concept of partitioning a large design into functional blocks and giving each block, along with its associated timing constraints, to a different design engineer or group of engineers. The register-transfer level (RTL) for each model is captured and synthesized independently, and the final physical netlist is handed over to a system integrator. The system integrator is responsible for “stitching” all of these areas together. Incremental design refers to the fact that as long as the interfaces between blocks/columns are tied down one can modify the RTL associated with a particular block, resynthesize that block, and rerun place-and-route on that block in isolation. This is much faster than having to rerun place-and-route on the entire design. It may be more appropriate to say that the incremental design tools “freeze” all of the unchanged blocks in place and they reimplement only the changed block(s) in the context of the entire design. This provides an advantage over modular design in which the other blocks are not present.